JP3742838B2 - Liquid crystal display - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display device capable of realizing a high-quality image by preventing light leakage due to ion (Ion) adsorption at a signal applying unit.
[0002]
A liquid crystal display device (Liquid Crystal Display: hereinafter referred to as LCD) has characteristics such as light weight, thinness, and low power consumption. Etc. are used. In particular, a TFT-LCD provided with a thin film transistor (hereinafter referred to as TFT) can realize a high-quality display and a large display device because it has excellent response characteristics and adapts to a high number of pixels. is there.
[0003]
[Prior art]
In such a liquid crystal display device, a storage-on-gate method as shown in FIG. 1 and a storage-on-common method as shown in FIG. Can be classified.
[0004]
As shown in FIG. 1, the storage-on-gate type liquid crystal display device includes a gate line 12 and a common line 14 formed in a signal applying unit 11 outside a display unit 10 on which an image is embodied on a substrate 19. Thus, the signal is applied to the inside of the display unit 10.
[0005]
In such a liquid crystal display device, the pixels in the display unit 10 all have the same structure, and the gate line 12, the data line 13, the common line 14, the counter electrode 15, the pixel electrode 16 and the thin film transistor 17 have the same shape. A number of constructed pixels are adjacent to each other.
[0006]
However, the outermost pixel adjacent to the signal applying unit 11 is different from other pixels in the display unit 10. That is, the outermost pixel has a structure in which no data line is formed in the direction of the signal applying unit 11.
[0007]
In the liquid crystal display device having such a structure, when a scanning signal is applied to one of the gate lines 12 and a display signal is applied to the data line 13, the intersection of the gate line and the data line to which the signal is applied. The thin film transistor 17 located in the vicinity of is turned on (TURN ON). Then, the display signal of the data line 13 is transmitted to the pixel electrode 16 through the thin film transistor 17, and a common signal is continuously applied to the counter electrode 15, so that an electric field is generated between the electrodes 15 and 16. .
[0008]
As a result, liquid crystal molecules (not shown) are parallel to the electric field due to dielectric anisotropy (in the case of positive dielectric anisotropy) or vertically (in the case of negative dielectric anisotropy). The light is transmitted to implement a predetermined image.
[0009]
The operation principle of the storage on common type liquid crystal display device shown in FIG. 2 is the same as that of the storage on gate.
[0010]
[Problems to be solved by the invention]
On the other hand, the conventional liquid crystal display device has the following problems. The gate line and the common line generate a voltage difference due to the difference between the DC (direct current) component signal of the gate line and the DC component signal of the common line. On the other hand, a pulse is applied to the data line, and a DC voltage of a specific component is swung to a positive voltage and a negative voltage for each frame with respect to the common voltage of the DC component. It is prevented from being maintained.
[0011]
However, in the prior art, as described above, the data line is not formed in the direction of the signal applying unit in the pixel adjacent to the signal applying unit. Accordingly, ion (Ion) adsorption occurs due to the voltage difference between the gate line and the common line, and the electric field generated thereby affects the pixels.
[0012]
In the case of normally black mode, the pixel at the outermost part that is switched due to the electric field partially generated by ion adsorption is light gray and light leakage occurs in the screen. There is a problem that the quality deteriorates.
[0013]
[Means for Solving the Problems]
The liquid crystal display device according to the present invention has been created to solve the problems of the prior art, and an object of the present invention is to extend the pixel electrode of the outermost pixel to the signal application portion. Accordingly, it is an object of the present invention to provide a liquid crystal display device that prevents light leakage due to ion adsorption at a signal applying unit.
[0014]
In order to achieve the object of the present invention, a liquid crystal display device according to the present invention includes a substrate, a signal applying unit in which gate lines and common lines are formed on the substrate, a data line, a counter electrode, and a pixel on the substrate. In a liquid crystal display device including an electrode, a plurality of pixels in which a thin film transistor is formed, and a display unit including a gate line and a common line extended from the signal application unit, the pixel electrode includes a body part and a branch part. The body part is parallel to the gate line, the branch part is composed of several branches and parallel to the data line, and the pixel electrode of the outermost pixel adjacent to the signal applying part has a plurality of branches. Is formed on the signal applying unit.
[0015]
The above objects, other features and advantages of the present invention will become apparent from the following description of the preferred embodiments of the present invention referred to below.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a liquid crystal display device according to the present invention will be described in detail with reference to the drawings.
As shown in FIG. 3, the liquid crystal display according to the present invention can be divided into a signal applying unit 110 and a display unit 100 according to whether or not the substrate 190 can implement an image.
[0017]
The signal applying unit 110 applies a gate signal and a common signal to the display unit 100 in order to implement an image, and a gate line 120 and a common line 140 are formed.
[0018]
The display unit 100 is a part of a substrate 190 on which an actual image is implemented. The display unit 100 includes data lines 130 arranged in a vertical direction, and is arranged in a matrix form substantially perpendicular to the data lines 130 to apply the signal. A gate line 120 extending from the unit 110 and a common line 140 extending from the signal applying unit 100 are formed in parallel with the gate line 120.
[0019]
Meanwhile, a thin film transistor 170 as a switching element is formed at the intersection of the gate line 120 and the data line 130.
[0020]
The display unit 100 forms an electric field overlapping with the counter electrode 150 formed in each pixel (Pixel) defined by the pair of gate lines 120 and data lines 130. Thus, the pixel electrode 160 is formed.
[0021]
Here, the pixel electrode 160 includes a body 160a and several branches 160b and 160c. The trunk portion 160 a is arranged in parallel to the gate line 120, and the branch portions 160 b and 160 c are arranged in parallel to the data line 130.
[0022]
Meanwhile, in the outermost pixel adjacent to the signal application unit 110, one or more branch portions 160 c of the plurality of branch portions of the pixel electrode 160 are formed on the signal application unit 110.
[0023]
The same voltage as that applied to the other branch 160b of the pixel electrode 160 is also applied to the branch 160c formed on the signal applying unit 110.
[0024]
The structure as described above operates as follows.
Since a data signal is applied to the plurality of branches 160 b and 160 c of the pixel electrode 160, a pulse signal that acts on an alternating current relative to the voltage of the common line 140 is applied.
[0025]
Accordingly, ion adsorption due to the voltage difference of the DC component between the gate line 120 signal and the common line 140 signal is prevented by an AC signal from the outside of the pixel, that is, a partial branch 160c of the pixel electrode formed on the signal applying unit 110. Is done. Also, ion adsorption and ion diffusion into the display unit 100 are prevented.
[0026]
So far, a storage on gate type liquid crystal display device in which the common line 140 is formed on the outer periphery of the pixel has been described.
[0027]
The description and operation of the storage-on-common type liquid crystal display device shown in FIG. 4 in which the common line 240 passes through the center of the pixel is the same as in the case of the storage-on-gate.
[0028]
In the scope of the principle of the present invention, various embodiments can be easily implemented by those having ordinary knowledge in the technical field to which the present invention belongs. Accordingly, the claims appended hereto are not limited to those detailed herein, but also include any embodiments based on the principles of the present invention.
[0029]
【The invention's effect】
As described above, the liquid crystal display device according to the present invention has the following effects.
In the present invention, the pixel electrode of the outermost pixel is formed up to the signal application unit, and ion adsorption due to the voltage difference between the gate line and the common line is prevented in the signal application unit.
[0030]
Therefore, since an unnecessary electric field due to ion adsorption does not occur, the light leakage phenomenon that occurs at the screen edge is prevented and the screen quality of the liquid crystal display device is improved.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a conventional liquid crystal display device.
FIG. 2 is a cross-sectional view of a conventional liquid crystal display device.
FIG. 3 is a cross-sectional view of a liquid crystal display device according to the present invention.
FIG. 4 is a cross-sectional view of a liquid crystal display device according to the present invention.
[Explanation of symbols]
100, 200 Display unit 110, 210 Signal application unit 120, 220 Gate line 130, 230 Data line 140, 240 Common line 150, 250 Counter electrode 160, 260 Pixel electrode 160a, 260a Body 160b, 160c, 260b, 260c Branch 170,270 Thin film transistor 190,290 Substrate

Claims (2)

A substrate,
A signal applying unit in which a gate line and a common line are formed on the substrate;
A liquid crystal display including a plurality of pixels on which data lines, counter electrodes, pixel electrodes, and thin film transistors are formed on the substrate, and a display unit including a gate line and a common line extended from the signal application unit. In the device
The pixel electrode is divided into a body part and a branch part. The body part is parallel to the gate line, the branch part is composed of a plurality of branches and is parallel to the data line, and is adjacent to the signal applying part. A liquid crystal display device, wherein a pixel electrode of an outer pixel has a part of a plurality of branches formed on the signal applying unit. The voltage of the same part as the voltage of the other branch of the pixel electrode of the outermost pixel is applied to some branches of the pixel electrode formed on the signal applying unit. Liquid crystal display device.

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